The guaranteed upper limit temperature of a laminated ceramic capacitor is determined based on the electrical insulation property and the high-temperature load reliability (the lifetime in a high-temperature load test). This guaranteed temperature is generally 85° C. for common consumer equipment and 125° C. for industrial equipment which is required to have high reliability.
In recent years, among laminated ceramic capacitors for industrial equipment, a laminated ceramic capacitor used in a high-temperature environment such as a laminated ceramic capacitor to be mounted on a vehicle is being required to have the high-temperature load reliability at a higher temperature of 150 to 175° C.
A dielectric ceramic composition appropriate for use in a laminated ceramic capacitor that meets such a requirement is disclosed for example in Japanese Patent Laying-Open No. 2011-207630 (PTD 1). The dielectric ceramic composition disclosed in PTD 1 is represented by a composition formula: 100 (Ba1-xCax) TiO3+aR2O3+bV2O5+cZrO2+dMnO (where R is at least one kind of metal element selected from Y, La, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, and a, b, c, and d represent a molar ratio), and satisfies each of the conditions: 0.03≦x≦0.20, 0.05≦a≦3.50, 0.22≦b≦2.50, 0.05≦c≦3.0, and 0.01≦d≦0.30.
It has been confirmed that the laminated ceramic capacitor in which the aforementioned dielectric ceramic composition is used has excellent high-temperature load reliability, namely has an MTTF (Mean Time To Failure) of 50 hours or more in a high-temperature load test in which a DC voltage with a field intensity of 20 V/μm is applied at a temperature of 175° C.
PTD 1: Japanese Patent Laying-Open No. 2011-207630